Adaptive primary immunity

Adaptive Primary Immunity: Cellular Defences

• T-lymphocytes: These are cellular defenders part of adaptive immunity, primarily involved in cell-mediated immune response. They mature in the thymus and are classified as either helper, cytotoxic or suppressor T-cells.

• Helper T-cells (T_h): Often referred as ‘conductors of immune symphony’, they coordinate the immune system’s response by releasing signals (cytokines) after identifying the presence of an antigen.

• Cytotoxic T-cells (T_c): Also known as ‘killer cells’, these are activated by Helper T-cells and play a pivotal role in directly defeating pathogens. They possess the ability to recognise and kill cells infected with viruses and other pathogens.

• Suppressor T-cells: They help in regulating immune response, preventing over activation of the immune system and protecting body cells from being accidentally targeted.

Adaptive Primary Immunity: Humoral Defences

• B-lymphocytes: Known as B-cells, originating from the bone marrow, they form the backbone of the antibody-mediated immune defence. B-cells detect pathogens with receptors on their surface and differentiate into Plasmablasts.

• Plasmablasts: These cells arise from the activation of B-cells and they churn out antibodies specific to the pathogen encountered.

• Antibodies: Also known as immunoglobulins, they are proteins released by plasmablasts that could identify, neutralise and help destroy pathogens. They work by binding to the antigens on the pathogen’s surface.

• Memory B-cells: They are an evolved result of primary immune reaction, providing long-lasting immunity. These cells “remember” the particular antigen that invaded the body and while encountering the same antigen in future, they swiftly produce a secondary, enhanced immune response.

Importance of Primary Adaptative Immunity

• Specificity: Adaptive immunity targets specific pathogens that the body has previously encountered, making its response effective and efficient.

• Diversity: Adaptive immunity can recognise and remember millions of different antigens.

• Memory: Adaptive immunity ‘remembers’ the antigen it has previously encountered, which allows a swift and enhanced immune response in potential future encounters.

• Self and non-self recognition: Adaptive immunity can differentiate between the body’s own cells and foreign cells, ensuring that the body’s own cells are not wrongly targeted during an immune response.